Battery-operated electronic devices, such as mobile telephones, tablet computers, and laptop computers, etc., have become very popular. Cases for these electronic devices typically surround the back of the device, and incorporate a clear plastic sheet that sticks to the screen of the electronic device to protect from scratching. However, these sheets often become dirty and/or scratched, delaminate from the screen, and have bubbles that impede viewing of the content on the screen. Further, the battery-operated device typically must be inserted within the case in a specific orientation. For example, a conventional mobile phone case surrounds the back of the phone and provides little to no protection of the phone's screen.
Almost all of these devices rely on rechargeable batteries, such as lithium ion or lithium polymer batteries, for electric power. Due to the desire to minimize battery-operated device size, weight, and cost, as well as limitations of conventional battery technology, device batteries typically have a small capacity and therefore must be frequently recharged. For example, batteries of some mobile telephones, such as mobile telephones with advanced processors designed to run a wide variety of applications, may need to be recharged more than once per day during periods of extensive device use. Recharging a battery typically requires that the battery be electrically coupled to a fixed electrical power source, such as a building's electrical outlet, via a power converter commonly referred to as a “charger” or an “adaptor,” thereby impairing the device's mobility. Accordingly, it is desirable to minimize battery-operated device battery charging from a fixed power source.
One possible way of reducing the need to charge a battery-operated device's battery from a fixed power source is to couple an external power source to the electronic device. In certain instances, the external power source contains an additional battery, a photovoltaic assembly, or both. The photovoltaic assembly generates an electric current in response to incident light, and the electric current charges the additional battery, and/or directly provides power to the device. Accordingly, coupling a photovoltaic assembly to an electronic mobile device may reduce, or even eliminate, the need to recharge the battery from a fixed power source.
Protective cases including photovoltaic assemblies have been proposed, for example, for use with mobile telephones and tablet computers. However, conventional photovoltaic assemblies are typically large and inflexible. Thus, cases incorporating these photovoltaic assemblies are typically bulky, thereby impairing the mobility, industrial design, and/or aesthetic properties of the mobile device that they are coupled to. For instance, one conventional mobile telephone case including a photovoltaic assembly is almost as thick as the mobile telephone itself, thereby significantly increasing the effective size and drastically changing industrial design of the telephone coupled to it.
Existing protective cases including a photovoltaic assembly are typically charged using either a USB cable or the onboard photovoltaic assembly. Charging via a USB cable requires that the mobile device be tethered by the cable, thereby restricting mobility, unless the device is removed from the protective case. Charging via the integrated photovoltaic assembly, on the other hand, typically requires removal of the mobile device from the case, before placing the case in sunlight for charging. If the battery-operated device is not removed from the case prior to photovoltaic charging, excessive temperature from sunlight exposure may cause the battery-operated device to shutdown, to prevent device damage.